With the development of Chinese economy, a tunnel boring machine (TBM) has been widely used in tunnel construction of water conservancy projects, railway transportation, subway projects, oil and gas pipelines, national defense and the like in recent years. During operation of the TBM, due to complicated working conditions, poor service environment and the like, the TBM has the characteristics of heavy load and impact, and finally, key weak positions of a main machine system of the TBM are worn and even broken.
The main machine system of the TBM mainly comprises a cutterhead, a front shield, drive electric motors, a main beam, gripper shoes, etc. A poor load condition is an important factor which causes fault of the main machine system of the TBM. To conduct anti-vibration design of the main machine and life estimation of key structural elements, the vibration condition of the main machine of the TBM and the strain condition of positions of the key structural elements must be mastered. A real-time monitoring system is built for monitoring vibration and strain conditions of key weak positions of the main machine system of the TBM, thereby reminding project builders to repair in time, avoiding further damage and also providing a basis for the improvement of vibration reducing solutions and the life estimation of the key structural elements.
Because the working conditions of the TBM are very bad, it is very difficult to monitor the state of the TBM. At present, there is no complete solution for monitoring vibration and strain of the main machine system of the TBM in China and abroad. Furthermore, in some theoretical dangerous points of key positions, due to the limitation of actual working conditions, sensors cannot be installed for direct measurement. Although some scholars or enterprises collect a small segment of vibration data in the tunneling process, the vibration data has a certain limitation because a small number of samples are collected.
Based on the above condition, the present invention carries out overall safety layout and local strengthening protection measures for the existing vibration and strain sensors, and provides an evaluation method for strain states of positions which cannot be measured, i.e., an equivalent mapping method, thereby building a set of vibration monitoring and strain monitoring systems for the tunneling process of the key positions of the main machine system of the TBM.